--- configure.orig	2007-12-12 22:25:45.000000000 +0100
+++ configure	2010-03-29 09:29:03.000000000 +0200
@@ -17563,7 +17563,7 @@
 int
 main ()
 {
-png_check_sig(NULL,0)
+png_sig_cmp(NULL,0,0)
   ;
   return 0;
 }